The confusion between the terms open kinetic chain and closed kinetic chain becomes even greater with application to the upper extremity. Upper extremity function is very difficult to define, due to the numerous shoulder positions and the great velocities with which the shoulder can move. Classifying exercises for rehabilitation of the upper extremity is very difficult due to the complexity of the joint. Many definitions and classification systems have been proposed; however, none of these entirely encompass rehabilitation of the upper extremity. Using previous classifications we have developed a Functional Classification System that is designed to serve as a template for upper extremity rehabilitation. This system has been designed to restore functional shoulder stability, which is dependent upon proper scapulothoracic and glenohumeral stability, and humeral control; all of these are in part mediated by neuromuscular mechanisms. The objective of our new Functional Classification System is to restore functional stability of the shoulder by reestablishing neuromuscular control for overhead activities.
Scott M. Lephart is with the Neuromuscular Research Laboratory, Sports Medicine Program, University of Pittsburgh, Pittsburgh, PA 15261. Timothy J. Henry is a doctoral student in exercise physiology/athletic training, University of Pittsburgh.